Technical Field
This invention relates to an electronic apparatus, a method of detecting a tap operation, etc.
Background Art
Various forms are considered for interfaces for users to input to electronic apparatuses, and may be e.g. an operation unit having keys, buttons, etc. or a touch panel also serving as a display unit. As the other input interfaces, techniques using tap actions (operations) are widely used. Here, the tap action refers to an action of tapping an electronic apparatus by a user using his or her hand or the like, and, in a broader sense, an action of applying an impact to the electronic apparatus. Further, the tap operation refers to operation input by the tap action.
The tap action is a useful user interface in an electronic apparatus in which an input device such as buttons is restricted. For example, in a wristwatch-type electronic apparatus, the buttons or the like are significantly restricted because reduction in size and weight is required and a simple configuration is required for realization of a user-friendly interface.
However, in order to detect the tap action, it is necessary to recognize a very short term of change of acceleration. For example, if sampling of acceleration signals is not performed with resolution of about 200 Hz, the possibility of false detection rises. Note that, the higher the resolution, the higher the power consumption. Namely, accuracy and power consumption have an inverse relation and finding good balance between usability and apparatus battery life is very difficult.
For example, PTL 1 discloses a technique of calculating an amount of activity and changing a detection cycle of an acceleration sensor based on the calculated amount of activity. PTL 1 describes an advantage of reducing power consumption of an activity meter by the technique.